package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.collection.CollectionUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.function.Function;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IUserService userService;


    @Override
    public Result isFollow(Long followUserId) {
        Long id = UserHolder.getUser().getId();
        Integer count = query().eq("follow_user_id", followUserId).eq("user_id", id).count();
        return Result.ok(count > 0);
    }

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //1.获取当前登录用户id
        Long userId = UserHolder.getUser().getId();
        String key = "follows" + userId;
        //2.判断是取关还是关注操作
        if (isFollow){
            //关注
            Follow follow = new Follow();
            follow.setFollowUserId(followUserId);
            follow.setUserId(userId);
            boolean flag = save(follow);
            if (flag){
                stringRedisTemplate.opsForSet().add(key, followUserId.toString());
            }
        }else {
            //取关
            boolean remove = remove(new QueryWrapper<Follow>().eq("user_id", userId).eq("follow_user_id", followUserId));
            if (remove) {
                stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result followsCommon(Long followUserId) {
        String key = "follows";
        Long userId = UserHolder.getUser().getId();
        //1.先获取当前登录用户和关注用户的关注列表
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key + userId, key + followUserId);
        if (CollectionUtil.isEmpty(intersect)){
            return Result.ok(Collections.EMPTY_LIST);
        }
        //解析用户id
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //根据id去查询这些用户
        List<User> userList = userService.query().in("id", ids).list();
        List<UserDTO> userDTOList = userList.stream().map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());
        return Result.ok(userDTOList);

    }
}
